Since the end of the World War 2, Italy adopted the US-designed M1 Garand rifle in .30-06 (7.62x63mm) and manufactured it under licence. This semi-automatic rifle proved itself wery well during WW2 but in the late 1950s it was seriously outdated and obsolete, so Italian military wanted a new rifle, chambered for the NATO-standard cartridge, 7.62x51mm. The most cost-efficient way to build a new rifle was to redesign the old good M1, and this was done by Pietro Beretta SPa. New gun, designated as Beretta BM59, was adopted in 1959 and served with Italian, Indonesian and Marocco armies. It should be noted that earliest BM59s were manufactured from available M1 parts, including rechambered barrels. In the late 1980s BM59 was rplaced in Italian service with Beretta AR70/90 assault rifles.

Basically, the BM59 can be described as re-chambered M1 Garand, with addition of the removable 20 rounds magazine and select fire trigger. Another addition was a flash-hider of NATO-standard diameter, which also served as a rifle grenade launcher. To launch grenades, one must turn on gas cut-off valve by raising grenade front sight, mounted on the gas block. If it will not be done, the excessive gas pressure will damage the rifle. BM59 is a gas operated rifle, with gas chamber and gas piston located under the barrel. Chamber locks by the rotating bolt with two massive lugs. Fire mode selector/safety switch is located at the front of the triggerguard, charging handle is attached to the gas rod and reciprocates during the fire cycyle.

BM59 was available in 4 modification:
* BM59 Mark I had a wooden stock with semi-pistol grip.
* BM59 Mark II had a wooden stock with pistol grip to achieve a better control during the full-auto fire;
* BM59 Mark III, or Ital TA, was a gun with a pistol grip and a metallick folding buttstock, and was intended for Mountain troops; BM59 Para was similar to BM59 Ital TA but had shorter barrel and shorter flash-hider, and was intended for paratroopers.
* BM59 Mark IV, had a heavier barrel and plactick stock, and was used as a light squad automatic weapon.